As well as good absorptive properties, primary requirements of absorbent articles are good fit and comfort. Various methods have been employed in the design and manufacture of absorbent articles so that they follow the contours of the user's body well and do not move out of place during use.
Patent applications WO 03/053301, EP 0 956 844, WO 03/047484, WO 02/087484, WO 02/085270, WO 03/059222, WO 02/087483, WO 02/085269 and related applications describe absorbent products which comprise a stiffening element that is intended to contribute to the three-dimensional shape of the products during their use.
EP 1 458 718 describes a disposable diaper having a region of low stiffness being a rectangular region along each side edge of the absorbent member. The low bending stiffness of this region allows the diaper to be bent upwards easily to join around the waist of the user.
EP 1 275 358 describes an absorbent article having a front absorbent region and a rear cushion region. The stiffness is higher in the front absorbent region, such that the shape of the raised region is maintained.
US 2004/0122407 discloses a sanitary napkin, the longitudinal central region of which has a higher flexure-resistance than the outer portions. In this way, the side regions are flexible enough that the sanitary napkin forms a cup-like trough under the wearers' genitals.
EP 0 572 033 discloses an absorbent article having zones which vary in stiffness. The article resists bunching and twisting during use. EP 1 102 824 discloses a sanitary napkin, the edges of which are less stiff than the center for comfort.
US2004/0204698 and US2003/0119401 describe an absorbent article having an air-formed unitary absorbent core. The core provides non-uniform lateral compression stiffness and predetermined bending in the article, as it has thinner regions at the edges. The core is thinner towards the front/rear edges as well as at the side edges.
There is still room for improvement in the comfort and fit of absorbent articles such as sanitary napkins. In particular, many of the earlier approaches to this problem involve cutting or otherwise removing parts of the absorbent cores of absorbent articles. However, this reduces the total amount of absorbent material which is present and thus provides lower security against leakage. Furthermore, cutting or otherwise removing parts of the absorbent core often results in wasted material, as the cut-out parts cannot always be used. Furthermore, many known products require additional stiffening elements.